Commuters face severe disruption this morning as Southern conductors walk out in a 24-hour strike.
Most services, including the Gatwick Express, are expected to run as normal, Southern have stated.
But there will be no Southern services between Clapham Junction and Milton Keynes Central via Kensington Olympia or Watford Junction, between Leatherhead and Guildford, or Rye – Ashford International shuttle services during the morning and evening peaks.
Rail tickets may be accepted on buses and different train lines - full details of which are on Southern's website.
Frustrated commuters giving up on cancelled or delayed trains and finding alternative routes to work is also expected to create chaos on the roads this morning.
Highways England tweeted: “Due to planned Rail Industrial Action today, traffic may be higher than normal. Please plan your journey and factor in delays.”
A Southern spokeswoman said: “We're aiming to run as full a service as possible next Monday for our passengers.
"We've made it clear to the RMT that we won't meet with them whilst they persist with wholly unnecessary industrial action."
Mick Cash, RMT general secretary, responded by saying Southern were ‘spinning lies’ about the impact of the action.
He said: “RMT repeats again today the call for genuine and serious talks that cut through the barrage of spin and hype from the company and which set for a framework for a safe and sustainable solution to Britain’s longest-running industrial dispute.”
The RMT union is striking over plans to have driver-only trains on Southern lines.
The union say this is unsafe – a claim dismissed by Southern, and by an independent report by the Office of Rail and Road in January.
For more information on the strike, visit http://www.southernrailway.com/your-journey/strike